Complete Guide to 80 Percent Lowers: Benefits and How-Tos
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What Is an 80 Percent Lower?
An 80 percent lower is an unfinished firearm lower receiver that has not yet been machined to completion. This component is considered “80% complete” because it lacks the cavities and holes required to house the trigger and other essential parts. For firearm enthusiasts, this provides an exciting opportunity to build a custom firearm from the ground up.
At Route 66 Guns & Ammo, conveniently located halfway between Las Vegas and Los Angeles, we help customers in Barstow, Hesperia, Apple Valley, Phelan, and Victorville create the perfect firearm. Although 80% Lowers are no longer legal in California, we wanted to write this article to help anyone with 80% lower that was registered before the ban, or to help anyone in another state.
Why Choose an 80 Percent Lower?
Building a firearm with an 80 percent lower offers several unique advantages:
Customization Options
With an 80 percent lower, you can design a firearm tailored to your exact preferences. From choosing the trigger assembly to selecting a custom finish, the possibilities are endless.
Educational Value
Assembling a firearm from an unfinished lower provides hands-on experience, helping you understand the mechanics of your weapon.
Cost-Effective Builds
Building your firearm can often save money compared to purchasing a fully assembled model.
Legal Benefits
In many regions, 80 percent lowers are not classified as firearms, meaning they don’t require a background check or serial number. However, always ensure compliance with local, state, and federal laws.
How to Complete an 80 Percent Lower
While completing an 80 percent lower requires some effort and the right tools, it’s a manageable process for most firearm enthusiasts. Here’s how:
Select Your Tools
To complete your 80 percent lower, you’ll need:
A drill press or handheld drill
An 80 percent lower jig for precision machining
Drill bits and end mills
Sandpaper for finishing edges
Set Up Your Jig
Secure the lower receiver into the jig according to the manufacturer’s instructions.
Ensure the jig is properly aligned to avoid errors during machining.
Drill and Mill the Receiver
Drill pilot holes for the trigger group and safety selector.
Use a milling machine or router to carve out the fire control cavity.
Smooth and Deburr
Sand down rough edges for a clean finish.
Check that all parts fit smoothly and operate correctly.
Assemble Your Firearm
Attach the remaining components, such as the trigger, stock, and upper receiver.
Test your completed firearm to ensure functionality and safety.
Types of 80 Percent Lowers
At Route 66 Guns & Ammo, we stock various types of 80 percent lowers to suit different firearm builds:
AR-15 80 Percent Lowers
Perfect for building lightweight, customizable rifles.
AR-10 80 Percent Lowers
Designed for larger-caliber builds, ideal for hunting or long-range shooting.
Polymer 80 Lowers
Lightweight and easy to machine, great for handgun builds.
Legal Considerations for 80 Percent Lowers
While 80 percent lowers are federally legal in the United States, it’s important to understand the regulations in your state or locality. For example:
• California: Requires serialization and registration of completed lowers. As of 2022 registration has closed, and 80% lowers can no longer be bought or sold in California.
• Nevada and Arizona: Generally have fewer restrictions, but always confirm local laws.
At Route 66 Guns & Ammo, we prioritize compliance and can guide you through the legal requirements for your area.
Tips for Building an 80 Percent Lower
• Use High-Quality Tools: Investing in reliable tools ensures precision and reduces errors.
• Work in a Well-Ventilated Area: Machining metal or polymer generates dust and debris.
• Follow the Manufacturer’s Instructions: Each lower and jig may have unique requirements.
• Seek Expert Advice: If you’re unsure about any step, consult experienced builders or visit us for hands-on support.
Start Building Your Custom Firearm Today
Building a firearm from an 80 percent lower is a rewarding and educational experience that lets you create a weapon tailored to your preferences. While we can’t sell you an 80% lower, we can sell you a regular one for your next build. Visit Route 66 Guns & Ammo to browse our selection of lowers, tools, and accessories. Proudly serving Barstow, Hesperia, Apple Valley, Phelan, and Victorville, we’re here to help you build your ideal firearm. Contact us today or stop by our store to get started.